Preparation of l-(carbamoyl)-n-(carbamoyloxy) thioformimidates from acetoacetamides

ABSTRACT

1-(CARBAMOYL)-N-(CARBAMOYLOXY) THIOFORMIMIDATES SUCH AS METHYL 1-(CARBAMOY)-N-(METHYLCARBAMOYLOXY)THIOFORMIMIDATE AND METHYL 1-(DIMETHYLCARBAMOYL)-N(METHYLCARBAMOYLOXY) THIOFORMIMIDATE ARE PREPARED BY THE STEPS OF (A) REACTING DIKETENE WITH AMMONIA OR AN AMINE TO OBTAIN AN ACETOACETAMIDE; (B) CHLORINATING THE PRODUCT OF (A) AT A TEMPERATURE OF -10 TO 70*C; (C) REACTING THE PRODUCT OF (B) WITH A NITROSATING AGENT IN THE PRESENCE OF METHANOL, ETHANOL, ISOPROPANOL, WATER OR THEIR MIXTURE; (D) REACTING THE PRODUCT OF (C) WITH A MERCAPTAN AND THEN ADDING A BASE; AND (E) REACTING THE PRODUCT OF (D) WITH EITHER (1) A CARBAMOYL CHLORIDE IN THE PRESENCE OF A BASE; OR (2) AN ISOCYANATE, OPTIONALLY IN THE PRESENCE OF A BASIC CATALYST; IN WATER OR ORGANIC SOLVENTS SUCH AS ACETONE AND METHYLENE CHLORIDE.

Patented Jan. 19, 1971 3,557,089 PREPARATION OF 1-(CARBAMOYL)-N-(CAR- BAMOYLOXY)THIOFORMIMIDATES FROM ACETOACETAMIDES Edward W. Raleigh, Wilmington, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware No Drawing. Filed Dec. 27, 1968, Ser. No. 787,614 Int. Cl. C07d 29/34 U.S. Cl. 260-239 16 Claims ABSTRACT OF THE DISCLOSURE 1 (carbamoyl) N-(carbamoyloxy)thioformimidates such as methyl 1-(carbamoyl)-N-(methylearbamoyloxy)- thioformimidate and methyl 1-(dimethylcarbamoyl)-N- (methylcarbamoyloxy)thioformimidate are prepared by the steps of (a) reacting diketene with ammonia or an amine to obtain an acetoacetamide;

(b) chlorinating the product of (a) at a temperature of to 70 C.;

(c) reacting the product of (b) with a nitrosating agent in the presence of methanol, ethanol, isopropanol, water or their mixtures;

(d) reacting the product of (c) with a mercaptan and then adding a base; and

(e) reacting the product of (d) with either (1) a carbamoyl chloride in the presence of a base;

(2) an isocyanate, optionally in the presence of a basic catalyst; in Water or organic solvents such as acetone and methylene chloride.

BACKGROUND OF THE INVENTION This invention relates to methods for preparing 1- (carbamoyl -N- carbamoyloxy) thioformimidates. More particularly this invention is directed to methods of preparing the thioformimidates by reacting diketene with ammonia or an amine, chlorinating the product of that reaction, then reacting the product with a nitrosating agent, reacting the resultant hydroxamoyl chloride with a mercaptan in the presence of a base, and then preparing the desired thioformimidate by reaction either with a suitable carbamoyl chloride in the presence of a base, or isocyanate optionally in the presence of a basic catalyst.

The product thioformimidates are useful as pesticides and can be prepared in the manner disclosed in copending application Ser. No. 728,739, filed May 13, 1968. They can also be prepared from glyoxylic acid in the manner disclosed and claimed in copending application Ser. No. 772,811, filed Nov. 1, 1968.

By the methods of this invention it is possible to prepare the thioformimidates of Formula 1 below in a fivestep process in which the first two steps can be operatively combined. By thus avoiding the necessity to separate and recover the intermediate compound the methods of this invention permit economic preparation of the compounds of Formula 1 below in very good yield.

SUMMARY In summary, this invention is directed to the preparation of 1 (carbamoyl) -N-(carbamoyloxy)thioformimidates of the following formula wherein R is alkyl of 1 through 4 carbon atoms or alkenyl of 3 through 4 carbon atoms; R, is hydrogen, alkyl of 1 through 4 carbon atoms, 5 me'thoxy, or cycloalkyl of 3 through 5 carbon atoms;

R, is hydrogen or alkyl of 1 through 4 carbon atoms; with the proviso that R and R can be joined and are alkylene of 2 through 6 carbon atoms, and with the limitation that R and R never total more than 7 carbon atoms; R, is alkyl of 1 through 3 carbon atoms, allyl or propargyl; and R is hydrogen or methyl;

(e) reacting the product of (d) with either (1) a carbamoyl chloride in the presence of a base; or 2) an isocyanate in the presence or absence of a basic catalyst; in water, acetone, methylene chloride, methyl ethyl ketone, or methyl isobutyl ketone.

The compounds of Formula 1 and their use as pesticides are described and exemplified in application Ser. No. 728,739, referred to above.

DESCRIPTION OF THE INVENTION The process of this invention used in preparing the compounds of Formula 1 comprises the five steps enumerated above, and more fully described as follows:

Step (a) The reaction of diketene with ammonia or an amine in the presence of Water or an inert organic solvent CHFO-(]1Hz+NH CHa-i JCH2ON in which R and R are as defined in Formula 1 above.

Equimolecular quantities of diketene and ammonia or an amine are gradually mixed in a solvent such as diethyl ether, benzene, methylene chloride, or water, with water the preferred solvent. The diketene can be added to a solution of ammonia or amine, or the ammonia or amine can be added to a solution of diketene, or both reactants can be added simultaneously to the solvent. It is preferred to add the diketene to an aqueous solution of ammonia or amine.

The reaction is carried out at a temperature between about 20 C. and 80 0, depending on the solvent used. If Water is used as solvent a reaction temperature of between about 0 C. and C. is preferred. The time of addition is not critical and depends upon the cooling capacity of the reaction equipment. For economy and convenience it is preferred to keep addition time to a minimum. Addition times of 30 to minutes are ordinarily adequate. Completion of the reaction can be observed when a stable pH of 68 is obtained.

At the conclusion of the reaction the product can be isolated by conventional techniques such as by evaporation of the solvent or extraction with an organic solvent, and can be purified by distillation. However, it is ordinarily preferred to run the step (a) reaction in water, and to use acetamide in the presence or absence of a solvent and is illustrated by the equation wherein R and R are as defined above.

If the intermediate product of step (a) has been isolated or purified, it is preferred to mix the product with water, cool the mixture and add chlorine. -If the step (a) product has not been isolated from the reaction medium of step (a) the product mixture is cooled and chlorinated as is. Suitable solvents include Water, methanol, ethanol, isopropanol and their mixtures.

The chlorination should be carried out at a temperature between about 10 C. and 70 C. and preferably between about 20" C. and 50 C. except when an alcohol solvent is used at which times temperatures below C. are preferred. The amount of chlorine used will vary from stoichiometric to molar excess but it is preferred to use stoichiometric amounts.

The chlorine is ordinarily added over a period of 30 to 60 minutes although it can be added more rapidly if desired. After addition is complete the mixture is stirred, usually for about 30 to 60 minutes, usually at a temperature of about 20 to 50 C. The reaction is complete when the color of the reaction mixture disappears.

Elemental chlorine is the preferred source of chlorine when water is the solvent, however other chlorinating agents, such as sodium, lithium and potassium hypochlorite can be used if desired, and sulfuryl chloride may be preferred when no solvent is used.

For economic reasons water is the preferred solvent and obviously when step (a) product is used without isolating the product from the solvent, step (b) is carried out in the solvent of step (a). When alcoholic solvents are used it is sometimes advantageous to operate using a heel process.

The reaction product of step (b) can be isolated, if desired, or it can be used directly without isolation in the reaction of step (c).

Step (c) Step (c) comprises formation of the hydroxamoyl chloride and is illustrated by the equation O (I31 5]) R2 wherein R is methyl, ethyl hydrogen, or isopropyl, and R and R are as defined above.

The product of step (b) and solvent, if not already present from step (b), are charged initially to a reaction vessel. The nitrosating agent is then added to the reaction mixture at such a rate that the temperature remains between 20 C. and 50 C. and the pH remains above 4.0. Preferably the nitrosation is carried out at a temperature between about 0 -C. and C. and above a pH of 4.5.

As indicated above, suitable solvents include methanol, ethanol, isopropanol, water, and their mixtures. The concentration of the product of step (b) in the solvent will ordinarily range between about and by weight.

Suitable nitrosating agents include the lower alkyl nitrites and nitrite salts such as sodium, potassium, and calcium salts in conjunction with a liberating acid such as hydrochloric. The nitrosating agent is used in approximately stoichiometric amounts based on the product of step (b).

4 The product of step (0) can be isolated if desired or it can be used directly in the reaction of step (d) without isolation. It is sometimes preferred to isolate the product of step (c) thus removing excess acid, prior to step (d), to cut down consumption of base in step (d).

Step (d) The hydroxamoyl chloride from step (c) is reacted with a mercaptan and a base in a solvent according to the equation wherein R is as defined above, and R is hydrogen, methyl, ethyl or propyl.

This reaction is carried out in the presence of water, methanol, ethanol, isopropanol or their mixtures, at a temperature between -l0 and 0, preferably between 0 and 40 C., according to one of the following alternate procedures: (1) The hydroxamoyl chloride, if isolated after step (c), is dissolved in a solvent along with a slight excess of mercaptan. An aqueous solution of base is then added to accept the HCl liberated during the reaction. This procedure is preferably carried out in methanol as a solvent. The product can be isolated by removing the solvent, preferably under reduced pressure, followed by filtration. (2) The hydroxamoyl chloride in the reaction medium of step (c)- is treated with a preprepared solution of a metal salt of a mercaptan or with the mercaptan itself, followed by addition of the aqueous base. More base is required for this procedure than in (1) above because of the additional acetic acid and hydrochloric acid which are present in the reaction mixture of step (c). The product can be isolated by simple filtration if desired.

Bases which are suitable acid acceptors for adjusting the pH are the hydroxides, carbonates and bicarbonates of sodium, potassium, calcium and magnesium. The final pH should be between 5 and 9 and a pH of about 7 is preferred.

As stated, the product can be isolated if desired, or alternatively if water is the solvent, the product mixture can be used as is in step (e). It is usually preferred to isolate the product prior to use in step (e).

Step (e) Conversion of the product of step (d) to the desired formimidate is carried out by reacting the product of step (d) with an isocyanate or carbamoyl chloride according to the equation wherein R R R R and R are as defined above. The reactions of step (e) are carried out in a solvent such as water, acetone, methyl ethyl ketone, methyl isobutyl ketone, or methylene chloride, at a temperature which can range from below l0 C. to the boiling point of the solvent. Anhydrous solvents are preferred to avoid posabout one hour at to C. After addition is complete sible side-reactions of isocyanate or carbamoyl chloride the reaction mixture is held at C. for 30 minutes, and with water. The reaction of step (e is facilitated by the then briefly sparged with nitrogen.

presence of a basic catalyst such as trimethylamine or To the resulting N,N-dimethyl 2-chloroacetoacetamide triethylenediamine. The reaction of step (e is carried is added 394 parts of ethanol. In a separate vessel 200 out in the presence of an equimolar quantity of a base parts of 36% hydrochloric acid is added to 145 parts of such as triethylarnine, trimethylamine or the hydroxides, sodium nitrite and 104 parts of ethanol in 100 parts of carbonates or bicarbonates of sodium, potassium, calcium water. The ethyl nitrite evolved is collected in a chilled or magnesium. Alternatively, the sodium salt of the prodtrap and 75 parts of the ethyl nitrite are subsequently net of step (d) can be formed by reaction with a metal 10 added to the ethanolic solution of N,N-dimethyl 2-chlorohydride such as sodium hydride. The resulting sodium acetoacetamide in about one hour at 5 C. The reaction salt can then be reacted with a carbamoyl chloride in an mixture is stirred at 5 C. for a further 4 hours and is inert solvent such as tetrahydrofuran to obtain products then allowed to warm slowly to ambient temperature. as obtained in the (e reaction. The reaction mixture, which contains dimethylcarba- The 1-(carbamoyl)-N-(carbamoyloxy)thioformimidate 15 moylformhydroxamoyl chloride, is then cooled to 10 products of step (e) can be isolated by conventional pro- C. and parts of 'methyl mercaptan are added followed cedures such as filtration or extraction. by the gradual addition of about 160 parts of 50% aque- Of the steps (a) through (e) the more important ous sodium hydroxide solution at 10 to 5 C., so are steps (b) and (c) which provide an advantageous that a stable pH of 7 is obtained. The resulting methyl method of preparing the hydroxamyl chloride intero l-(dimethylcarbamoyl) N hydroxythioformimidate is mediate. A preferred sequence of reaction is to chlorinate isolated by filtration, washed with water, and dried. and nitrosate in step (b) and (c) reactions, a previously To a suspension of parts of methyl l-(di'methylobtained acetoacetamide prepared by any suitable process oarba=moyl)-N-hydroxythioformimidate and /2 part of step (a), and follow the nitrosation with the steps ((1) triethylenediamine in 350 parts of acetone at 40 C. is and (e).

25 added slowly 27 parts of methyl isocyanate. The tempera- The process of this invention is further illustrated in ture of the reaction ma'ss rises to 58 C. After the temthe following examples wherein parts and percentages perature of the reaction mass has subsided to 25 C., the are by weight unless otherwise noted. solvent is evaporated under reduced pressure, and the resulting residue recrystallized. Recrystallization from ben- EXAMPLE I 30 zene gives one isomer of methyl l-dimethylcarbamoyl-N- To 86 parts of a 25% aqueous solution of dimethyl- (methylcarbamoyloxy)thioformimidate, melting point 109- amine is added 200 parts of water, followed by the addi- 110 C. Recrystallization from water gives the other tion of enough diketene at 20 to 30 C. to give a stable isomer of methyl 1-(dimethylcarbamoyl)-N-(methlycarpH of 7; 41.3 parts of diketene are required. The resulting barnoyloxy)thioformimidate, melting point 101103 C. N,N-dimethyl acetoacetamide is isolated by extraction 3 The compounds of Table I are prepared by the procewith methylene chloride followed by evaporation of the dures of Example 1, using the mercaptans, amines and isosolvent. To 129 parts of N,N-dimethyl acetoacetamide so cyanates listed in place of the methyl mercaptan, diobtained is added 141.7 parts of sulfuryl chloride over methylamine and methyl isocyanate of 'Example I.

TABLE I Mercaptan Amine Isocyanate Product Ethyl mercaptan Dimethylamine Methyl isocyanate.... E31311-(dimethylca1bam0yD-N-(methylcarbamoyloxy)thioiormirni- Allyl mercaptan do .110 Allyl 1-(dimethylcarbamoyl)-N-(methy1carbamoyloxy)thiofonnimidate. But- 2-enyl l-(dimethylcarbarnoyb'N-(ethylcarbamoyloxy)thioiorm- But-Z-enyl mereaptan lo Ethyl isocyanate Isopropyl mercaptam--. Allylisoeyanate Isigitgigg: 1-(dimethylcarbamoyl)-N-(allylcarbamoyloxy)thioform- Methyl mercaptan Propargy1isocyanate Mtialtgrifilalitdhnethylcarbamoyl)-N-(propargylcarbamoyloxy)thioform- Propyl mercaptan Methyl isocyanate.... Plgrrlniylateli-(dimethylcarbamoyl)-N-(methylcarbamoyloxy)thioform- Allyl mercaptan do Allyl isocyanate Aggie-1 (dimethylcarbamoyl)-N-(a1lylearbamoyloxy)thioformimi- Isopropylmercaptan do Methyl isocyanate Istiilplritgyll-(dimethylcarbamoyl)-N-(methylcarbamoyloxy)thioform- Butyl mercapttm do do BL533;l-(dimethylcarbamoyl)-N-(methy1earhamoyloxy)thiofomrimisec-Butyl mercaptan ..do ..do Beg-gaggl-(dimethylcarbamoyl)-N(methylcarbamoyloxy)thioiormtert-Butyl mercaptan d0 ..do test-11531113:1-(dimethylcarbam0yD-N-(methylcarbamoyloxy)thioform- Methyl mercaptan d0 Ethyl isocyanate lvleltzfite l l-(dilnethylcarbarnoyD-N-(ethylcarbamoyloxy)thioformimi- Butylmercaptan .(1o do l-(dimethylcarbamoyD-N-(ethylcarbamoyloxy)thiotonmimi- Methyl mercaptan do Isopropyl isocyanate.- MieItnhglltL-tdimethylcarbamoyl)-N-(isopropylcarbamoyloxy)thioform- Butyl mercaptan ..do d0 Butryiligimethylcarbamoyl)-N-(isopropylcarbamoyloxy)thiofonn- Allylmercaptan ..do Propylisocyanate Aggie.l-(dimethylcarbamoyD-N-(propylcarbamoyloxy)thioiormimi- Methyl mercaptau do Allyl isocyanate Maggi l-(dimethylcarbamoyl)-N-(a11y1carbamoy1oxy)thioformimi- Butyl mercaptan do ..do B15233} 1-(dimethylcarbarnoyl)-N-(a1lylcarbamoyloxy)thioformimi- Allylmercaptan do Propargyl isocyanate.. Aggldaltdimethylcarbamoyl)-N-(propargylearbamoyloxy)thioform- Methyl mercaptan Methylamine Methyl isocyanate.... Methyl l-(methylcarbamoyl)-N-(methylcarbamoyloxy)thiotormimr Do Butylamine do Methgl- 1(butylcarbamoyD-N-(methylcarbamoyloxy)thioformimi- Isopropylmercaptan Cyclopropylamine do Ispglig l g-(gyclopropylcarbarnoyl)-N-(rnethylcarbamoy1oxy) thio- Allyl mercaptan N,O-dimethy1hydroxylamine Ethyl isocyanate Aliyglli-ltnlglrzrgthoxy-N-methylcarbarnoyl)-N-(ethylcarbamoyloxy) Ethyl mercaptan Isopropylamine Allylisocyanate Etnl 1-(iSopr0pylcarbam0yD-N-(allylcarbamoyloxy)thioformimi- TABLE I.Co ntiuued Mercaptan Amine Isoeyanate Product Methyl mercnptan Ethylamine Propargyl iseyauate Mtc-ithyl l-(ethylcarbamoyl) N-(propargylcarbamoyloxy)thiofonuinriate. D0 Diethylarnine Methyl is0eynnate Mgthyl l-(diethylearbamoyl)-N-(luethylcarbamoyloxy)thiofonuimiate. D0- Diisopropyleiuine l0 Methyil 1 (diisopropylcarbamoyl)-N-(methylcarbamoyloxy)thioformimi ate. Do Aziridino do Metlyl 1-(aziridinocarbouyl)N(methylcarbamoyloxy)tlliofonnimi- 2], G. De llexahydroazepiue do Methyl 1-(hexahydroazepiuocarbonyl)-N-(u1etl1ylcarbamoyloxy)thioformimidato. D0 lyrrolidiue do Meth l l-(pyrrolidiuocarbouyl)N-(niethylcarbamoylOxy)thlol'ormirni ate. Do Methyl-amine Allyl isoeyanate Methyl 1-(methylcarbamoyl)-N-(allylearbanroyloxy) thioforminlidate Do N,O-dimethylhydroxyla e Methyl isocyauate Methyl 1-(N-methoxy-N-methylcarbanroyl)-N-(methylcarbaiuoyloxy)thiol'onnimidate. Do N-nrethyl-N-ethylamiue Allyl isoeyanate Mfethyl 1:fiNgmethyl-N-ethylearbamoyl)-N-(allylearbamoyloxymnw onnuni a e. Ethyl mercaptun Piperidiue d0 Ethyl 1-(piperidiuocarbonyl)-N-(allylcarbamoyl0xy)thiofoimimidate D0 ..d0 Butylisoeyanate Etihyl 1-(piperidinoearbonyl)-N-(butylcarbamoyloxy)thiolorminnate. Butyl mercaptan do Methyl isoeyanate Blflliyl l-(pperidinocarbonyl)-N(methylcarbamoyloxy)thio orrnimi ate. D0 clo Butyl isocyanate Bitlltyl1-(piperidinoearbonyD-N-(butylcarbamoyloxy)thioformirniate. Methyl mereaptan N-methyl-N-butylamine Methyl isocyanate Mefihyl1-(N-nethylN-butylearbamoyl)-N-(methylearbamoyloxy)- t ioformimi ate. Ethyl mereaptam- Ammonia do Ethyl l-earbamoyl-N-(methylcarbamoyloxy)thioformimidate. Allyl mercaptan do do l Allyl l-carbamoyl-N-(methylearbamoyloxy)thioformimidate. But-Z-enyl mereaptan do Ethyl isoeyanate But-Z-enyl1-carbamoyl-N-(ethylearbamoyloxy)thioformimidate. Isopropyl mercaptan. do Allyl isoeyanate Isopropyl l-carbamoyl-N-(allylearbamoyloxy)thiofonnimidate. Methyl mereaptan do Propargyl isoeyanate Methyl l-carbarnoyl-N-(propargylearbamoyloxy)thioformimidate. Propyl mereaptan. do Methyl isocyanate Propyl l-earbamoyLN-(ruethylcarbamoyloxy)thioformimidate. Allylmercaptan d0 Allyl l-carbamoyl-N-(allylcarbamoyloxy)thioformimidate. Isopropyl mercaptalL d0 Isopropyl l-carbamoyl-N-(methylcarbamoyloxy)thioforrnimidate. Butyl mereaptan tlo Butyl l-earbamoyl-N-(methylearbamoyloxy)thioformimidate. see-Butyl mercaptarr d0 see-Butyl l-carbarn0y1-N-(methy1earbamoyloxy)thiofonnimidate. tert-Butyl rnercaptan. d0 ..do tert-Butyl 1-carbam0yl-N-(methylearbamoyloxy) thiofonnimidate. Methyl mercaptan do Ethyl is0cyanate Methyl l-carbamoyl-N-(ethylearbamoyloxy)thiol'onnimidate. Butyl mereaptaiL do do Butyl 1-earbam0yl-N-(ethylcarbamoyloxy)thioforrnimidate. Methyl mercaptan d0 l Isopropylisocyanute Methyl 1-earbamoyl-N-(isopropylcarbnrnoyl0Xy)thi0for-mimidate. Butyl mercaptan d0 d Butyl l-carbamoyl-N-(isopropylcarbamoyloxy)thioformimidate. Allyl mereaptan (lo Allyl Learbamoyl-N-(isopropylcarbamoyloXy)thioformimidate. Do do n-Iropyl1socyanate Allyl1-carbamoyl-N-(u-propylearbamoyloxy)thiolormimidate. Methyl mereaptau, (lo Allyl isocyanate Methyl l-carbamoyl-N-(allylcarbamoyloxy)thioformirnidate. Butyl mereaptau .(lo Ally] isocyanate Butyl1-earbamoyl-N-(allylearbamoyloxy)thiolormimidate. Allyl Inereaptau ,do Propargyl isoeytmate Allyl l-carbamoyl-N-(propargylcarbamoyloxy)thioformirnidute.

EXAMPLE II I claim:

p 1. A process for preparing alkyl 1-(carbamoyl)-N- To a stirred suspension of 48 parts of 50% sodium 40 hydride and mineral oil in 648 parts of tetrahydrofuran is (Carbamoyloxy)thloformumdates of the formula added portion-Wise over a one-hour period 114 parts of (1) R3 0 0 RA methyl 1-(carbamoyl)-N-hydroxythioforlmimidate. The l l 0 g temperature is maintained at to C. After subsidence of hydrogen evolution, 107.5 parts of dimethylcarbamoyl 2 1 5 chloride is added dropwise at l525 C. Stirring is conh tinued for one hour after the completion of addition. The W cram inorganic solids are then removed by filtration and the R is alkyl of 1 through 4 carbon atoms or alkenyl of 3 methyl l-carbamoyl N (dimethylcarbamoyloxy)thiothrough 4 carbon atoms; formimidate is recovered by removal of the solvent under R is hydrogen, alkyl of 1 through 4 carbon atoms, reduced pressure. methoxy or cycloalkyl of 3 through 5 carbon atoms; The compounds of Table II are prepared according to R is hydrogen or alkyl of 1 through 4 carbon atoms; the procedures of Example II, using the N-hydroxythiowith the proviso that R and R can be taken together formimidates and carbamoyl chlorides listed in place of and are alkylene of 2 through 6 carbon atoms, and methyl l-(carbamoyl)-N-hydroxythioformimidate and diwith the limitation that R and R never total more than methylcarbamoyl chloride. 7 carbon atoms;

TABLE II N -l1 ydroxythioiormimidate Carbamoyl chloride Product Methyl 1-carbam0yl N-hydroxythioformimidate N-allyl-N-methylcarbamoyl chloride Methyl l-earbamoyl-N-(N-ally1N-methylear-bamoyloxy)thiofonnimidate. Do N-methyl-N-propargylcarbamoylchloride Methyl l-carbamoyLN-(N-methyl-N-propargylcarbamoyloxy) thiofonnimidate. D0 N-methyl-N-propylcarbamoyl chloride Methyl l-carbarnoyl-N-(N-methyl-N'propylearbarnoyloxyhhioformimidate. Do N-cthyl-N-methylearbamoyl chloride Methyl 1'carbamoyl-N-(N-ethyl-N-methyl- I carbamoyloxy)thiofomrimidate. Methyl l-methylcarbamoyl-Nhydroxyt]uoformlmidate..- Dunethylearbarnoyl chloride Methyl l-(methylcarbamoyl)-N-(di1nethylcarbamoyloxy)thiofon'nimidate. Methyl 1-dunethylearbam0yl-N-llydroxytlliolonnimldate d0 Methyl l-(dimethylcarbarnoyD-N-(dimethyl carbamoyloxy)thioformimidate. Methyl 1-eyclopentylcarbamoyl-N-hydroxythiofomnmld0 Methyl l-(eyelopentylearbamoyl)-N-(didate. methylcarbamoyloxy)thioformimidate. Propyl 1-carbamoyl-N-l1ydroxytluofurnunudate .110 Propyl I-carbamoyl-N-(dinlotllylearbamoyloxy)thiof0i'n1imidate.

Ethyl l-carbamoyl-N-llydroxytluol'orluilnldnte "do Ethyl l-carbamoyl-N-(dimethylearbanroyloxy)thioforn1imidate.

Butyl 1-earban10y1-Nl1ydroxytlnol'onuumdate do Butyl 1 carbamoyl-N-(dimethylearbamoyloxy)thioformimidate.

R is alkyl of 1 through 3 carbon atoms, allyl or propargyl; and R is hydrogen or methyl;

by the steps comprising:

(a) reacting diketene with ammonia or an amine in the presence of water, or an organic solvent at a temperature of from about 20 C. to 80 C.;

(b) chlorinating the product of step (a) at a temperature between about l C. and 70 C. in the presence or absence of water, methanol, ethanol, isopropanol or their mixtures;

(c) reacting the product of step (b) with a nitrosating agent, in the presence of methanol, ethanol, isopropanol, water, or their mixtures, at a temperature between about 20 C. and 50 C. and a pH above 4.0;

(d) reacting the product of step (c) with an alkyl mercaptan of the formula R SH, wherein R is as defined above; and then raising the pH to the range of -9 by the addition of a hydroxide, carbonate or bicarbonate of sodium, potassium, calcium or magnesium;

(e) reacting the product of step (d) with (1) an appropriate carbamoyl chloride in the presence of a base; or (2) an appropriate isocyanate in the presence or absence of a basic catalyst; in water, acetone, methylene chloride, methyl ethyl ketone or methyl isobutyl ketone.

2. The process of claim 1 wherein step (a) is carried out in water.

3. The process of claim 1 wherein step (a) is carried out at a temperature between about 0 C. and 50 C.

4. The process of claim 1 wherein step (b) is carried out at a temperature between about 20 C. and 50 C.

5. The process of claim 1 wherein step (b) is carried out in water.

6. The process of claim 1 wherein the product of step (b) is isolated and step (c) is carried out in ethanol.

7. The process of claim 1 wherein step (c) is carried out in water using sodium nitrite and hydrochloric acid as the source of nitrous acid.

8. The process of claim 1 wherein step (c) is carried out at a pH above 4.5, and a temperature between about 0 C. and C.

9. The process of claim 1 wherein step (e) is carried out using an isocyanate and trimethylamine or triethylenediamine as the basic catalyst.

10. The process of claim 1 wherein step (e) is carried out using a carbamoyl chloride and triethylamine, trimethylamine, or a hydroxide, carbonate or bicarbonate of sodium, potassium, calcium or magnesium as the base.

11. The process of claim 1 wherein step (e) is carried out in acetone, methylene chloride, methyl ethyl ketone, or methyl isobutyl ketone.

12. A process for preparing alkyl 1-(carbamoyl)-N- (carbamoyloxy)thioformimidates of the formula s fl R4 o II R2 R5 wherein R is alkyl of 1 through 4 carbon atoms or alkenyl of 3 through 4 carbon atoms;

R is hydrogen, alkyl of 1 through 4 carbon atoms, methoxy or cycloalkyl of 3 through 5 carbon atoms;

R is hydrogen or alkyl of 1 through 4 carbon atoms; with the proviso that R and R can be taken together and are alkylene of 2 through 6 carbon atoms, and with the limitation that R and R never total more than 7 carbon atoms;

R, is alkyl of 1 through 3 carbon atoms, allyl or propargyl; and

10 R is hydrogen or methyl;

by the steps comprising:

(1) chlorinating an appropriate acetoacetamide at a temperature between about 10 C. and 70 C. in the presence or absence of Water, methanol, ethanol, isopropanol or their mixtures;

(2) reacting the product of step (1) with a nitrosating agent at a temperature between about and 50 C. in the presence of methanol, ethanol, isopropanol, water, or their mixtures;

(3) reacting the product of step (2) with an alkyl mercaptan of the formula R SH, wherein R is as defined above; and then raising the pH to the range of 5-9 by the addition of a hydroxide, carbonate or bicarbonate of sodium, potassium, cal cium or magnesium;

(4) reacting the product of step (3) with (1) an appropriate carbamoyl chloride in the presence of a base; or (2) an appropriate isocyanate in the presence or absence of a basic catalyst; in water, acetone, methylene chloride, methyl ethyl ketone or methyl isobutyl ketone. 13. The process of claim 12 wherein step (1) is carried out in water.

a 14. The process of claim 12 wherein step (1) is carried out at a temperature between about 20 C. and 50 C.

15. The process of claim 12 wherein step (2) is carried out in water using sodium nitrite and hydrochloric acid as the source of nitrous acid.

16. The process of claim 12 wherein step (4) is carried out in acetone, methylene chloride, methyl ethyl ketone, or methyl isobutyl ketone.

References Cited UNITED STATES PATENTS OTHER REFERENCES Chem. Abstracts, vol. 69, 1968, 35430s.

Chemische Berichte, 88, Nov. 1, 1955, pp. -133.

LEWIS GO'ITS, Primary Examiner E. G. LOVE, Assistant Examiner U.S. c1. X.R. 

